remove unused class member

  delete balance;

  delete irregular;

  delete[] weight;

  for (int i = 0; i < nimbalance; ++i)

    delete imbalance[i];

  delete[] imbalance;

  int nimbalance;               // number of imbalance weight computes

  class Imbalance **imbalance;  // list of imbalance compute classes

  double *weight;               // per (local) atom weight factor or NULL

  class Balance *balance;

  class Irregular *irregular;